Sound-amplifier for talking-machine



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SOUND AMPLIFIER FOR TALKING MACHINES APPLICATION FILED IIIAYIS. :919.

1,358,706. Y Patented Nov. 16, 1929.

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Il N5 5 6&7 2' @mm1/Ion UNITED srArEs PATENT omer..

JOHN E. CHRISTENSEN,

-F CHICAGO, ILLINOIS.

SOUND-AMPLIFIER FOR TALKING-MACHINEC.

'0 all whom it may conca/fn:

Be it known that I, JOHN E. Ciinis'rnN SEN a citizen of the United States, residing at hicago, in the county of Cook and Stato of Illinois, have invented new and useful Improvements in Sound-Amplifiers for Tall ing\/[acliines, of which the following is a specification. y

This invention relates to sound amplifiers or horns employed in connection .with phonographs and other sound reproducing machines, and its object is to provide. a horn of novel andA improved construction, and design, whereby the soundsl are rendered soft and mellow, and all harsh noises are eliminated or reduced to a minimum.

The object stated is attained by means of acombination and arrangement of parts to be hereinafter described and claimed, andV in order that the same may bebetter understood, reference is had to the accompanying drawing formingl a part of this specification.

In the drawin Figure 1 is a' horn, and

Fig. 2 is a cross-section thereof.

Referring specifically to the drawings, the horn or sound amplifier is a resonant dou ble-walled structurecf thin wood of suoli quality as is used in violin, guitar and similar musical instruments having a'hollow resonant body. The outer wall of the horn is shown at 5 and the inner wall at 6, these walls being spaced to provide an air chamber 7 which is closed at the outer end'of the horn by a transverse wall Sextending between the walls 5 and 6 at this end of the horn. The inner end of the air chamber is also closed by a transverse wall 8a. The

' walls 5 and 6 converge rearwardly and the air chamber is therefore fia-red toward the outer end of the horn.

The shape of the horn, in cross-section, is, preferably square, and it is flared in the direction of the outer end.

A suitable distance back of the outer end of the horn, the inner wall 6 has a pair of alined opposite openings 9 forming soun holes which open from the interior of the horn into the air chamber 7 surrounding the same. The air chamber is therefore cempletely closed in except where it opens into the interior of the horn.

The sound eniitted by the horn may be further modified by providing,anieans `for ingitudinal section of thel speciscaiion of Lettersratent. Patented NOV` 16, 1920 Application .filed nay i9, i919.

Serial yNo. 298,221.

partly or completely closing the sound holes 9, the saine comprising a pair of damper slides 1() carried by the branches 11 of a fork which straddles the opposite walls 6 in which the sound holes are made. The fork branches pass loosely through apertures in opposite portions of the walls 5, and on the outside of the horn they are connected to an operating handle 12. By sliding the forkf transversely of the horn, inwardly or outwardly, ily positioned to cover or uncover the sound holes 9 to obtain the desired tone quality. When the horn is built into a cabinet, it will be understood that the handle 12 must project through an aperture in the Wall of the same.

The fork branches 11 are slightly resilient rso that the slides are held snugly in contact with the wall 6v i To limit the stroke of the slides, the portions of the fork branches extending across the space between the walls 5 and 6, are fitted with two spaced abutinents composed of felt washers 13 held against inward movement by suitable means, such as cotter' pins 14. Thus one or the other of a air of washers strikes the walls 5 and 6 -as the fork is shifted, making the action noiseless, and saving the parts from being 4scratched or marred.

i To the rear or inner end of the .horn is secured an elbow 'l5 having a sound conduit 16 opening into the horn. of the horn meets the elbow, top, and side Where this 'endlthe slides .10 are readreinforcing blocks 17 and 18, respectively,

are glued over the joint.

The upper. end of the elbow 15 maybe secured to the base board 19 which supports the turn-table, thc sound arm being fitted to the elbow in-the usual manner.

By the construction hereinbefore described a hollow resonant body is provided for the horn, said body being similar to the body of a violin, guitar or other stringed musical instrument, and the sounds passing through the horn are considerably modified, their qualities being improved.

I cla-im:

1. A talking machine horn having a hollow resonant body formed by spaced inner and outer walls, with sound `noles in oppo site portions of the inner wall and opening into the space between the inner and outer walls, dampers controlling the sound holes, and a fork straddling the opposite walls having the sound holes and carrying the dempers, the branches of the fork having an actuating handle Wall.

passing through the outer 5 l '2. A talking mach-ine horn having a hol- K 10W resonant bodyformed by spaced inner and outer walls,

with sound holes in opposite portions of the inner wall und opening into the space between the inner and outer 10 wells, dempers c ontrolling the sound holes,

and 'a fork straddling he opposite wells having the sound holes and carrying the dempers, the branches or" the fork havingv an actuating handle passing through the outer Wall and provided between 'said Wall l and the inner Wall with stops to limit she travel of the'fork.

in testimony whereof aix my signature.,

foi-nr in, 

